Stop motion for twisters



Dec. 2, 1.952 T. M. RIPLEY ETAL STOP MOTION FOR TWISTERS Filed July 23, 1951 4 sheat s-Sheet 1 Y INVENTORSZ Tnomns M. RIFLE)? CARSON R ELLIS s FRANK G. Powfi'ks.

ATTORNEY:

1952 Y T. M. RIPLEY ET AL 2,619,78

STOP MOTION FOR TWISTERS Filed July 25, 195 4 Sheets-Sheet 2 INVENTORSI Thomas M. RIPL Y. "t CARsoN P Furs I FRANK G. Pawms.

4 ATTORNEYS.

D 2, 1952 1'. M. VRIPLELY ET AL 2,619,7 9

STOP MOTION FOR TWISTERS.

Filed July 25, 1951 4 Sheets-Sheet 3 THOMAS M. E'nPuEY.

CARsoIv E ELLIS 9 FRANK G. Poweres.

' ATTORNEYS INVENTORSZ Patented Dec. 2, 1952 STOP MOTION FOR TWISTERS Thomas M. Ripley, Aberdeen, Carson P. Ellis, Pinehurst, and Frank G. Powers, Aberdeen, N. 0., assignors to Robbins Mills, Inc., New York, N. Y., a corporation of New York Application July 23, 1951, Serial No. 238,098

Claims.

This invention relates to yarn processing machinery and more especially to an improved stop motion for yarn twisting machines and the like.

It is Well known to those familiar with the art that a twister frame or machine has a creel with yarn packages thereon from which strand of yarn pass downwardly and, in some instances, each of the strands of yarn passes over and around a top roll which normally rests upon a driven bottom roll, and then the yarn passes between the top and bottom rolls and half around the bottom roll after which the yarn passes through a corresponding yarn guide. The yarn then passes through the usual traveler mounted on a twister ring for directing the twisted yarn onto a bobbin or spool.

The twist is effected in the yarn by virtue of the movement of the traveler around the bobbin in directing the yarn thereto and it sometimes happens that the twist does not extend all the way along the strand from the traveler up to the rolls with the result that the yarn is easily broken between the rolls and the traveler or the strand of yarn may become parted due to various other reasons well known to those familiar with the art.

Heretofore, upon parting of the yarn, the top r011 would continue to rotate in engagement with the bottom roll, because of the bottom roll being constantly driven; In so doing, the top roll would take upthe yarn from the-creel and it often happened that a substantial number of turns of yarn were wound about the top roll before the parted end of the yarn was discovered by an operator with the result that the turns of yarn wound about the top roll would have to be removed therefrom and discardedor the broken end would become entangled in nearby ends passing between adjacent rolls thus causing additional loss of yarn. It is evident that this not only required considerable time on the part of the operator but also resulted in a considerable amount of waste thereby relatively increasing the cost of the twisted yarn.

It is, therefore, a primary object of this invention to provide means operable automatically upon the yarn being parted for elevating the top roll out of engagement with the bottom roll thus preventing further rotation thereof although the bottom roll continues to rotate.

More specifically, it is an object of this invention to provide a pivoted roll lifter support, for each of the top rolls, which has a yarn guide thereon and a wedge-shaped roll separating or lifting member oscillatably mounted thereon, the sharp edge of the lifting member normally being spaced closely adjacent the bite of the rolls. After the yarn passes beneath the bottom roll, it extends through the yarn guide extending from the roll lifter support and then downwardly through the traveler to the bobbin whereby the tension in the yarn serves-to hold the roll separating member out of engagement with the rolls. On the other hand, upon undue slack occurring in the portion of the yarn extending between the rolls and the traveler or upon the strand being parted in this zone, the sharp end of the roll separating member frictionally engages the top and bottom rolls at the bite thereof and, due to the peripheral surfaces of the rolls moving in a direction away from the roll lifter support, the roll separating member will be pulled between the biteof the rolls and will thus raise the top roll out of engagement with the bottom r011.

It i another object of this invention to provide a twister stop motion of the type described with a shaft on which the top roll lifter supportsare pivotally mounted in off-center relation so the center of gravity of each of the top roll lifter supports is disposed between the shaft and the bottom roll and to provide traverse limiting means fixed on the shaft for limiting pivotal movement of each top roll lifter support. This traverse limiting means is so arranged as to prevent inward movement of the roll separating member upon the yarn being parted and also limits outward movement of the roll lifter support so the top roll lifting or separating member is held in a semi-operative position closely adjacent the bite of the top and bottom rolls as the yarn, under tension, passes through the yarn guide on the roll lifter support.

It is still another object of this invention to provide a shaft locking mechanism or clutch mechanism for the shaft on which the roll lifter supports are pivotally mounted and to further provide an outturned handle on at least one end of said shaft for manipulation by an operator. The shaft looking or clutch mechanism includes a bearing member fixed to the frame of the twister or to one of its roll stands in which the shaft is oscillatably mounted and the bearing member is provided with at least one spring loaded detent therein. A collar is fixed on the shaft adjacent the bearing member and is provided with a pair of circularly spaced openings or cavities therein which are so positioned that the detent will engage one of the openings when the shaft is moved in one direction by the operator to lock the shaft in a first position. When the shaft is locked in this position, the means on the shaft for limiting inward and outward movement of each of the roll lifter supports will permit the support to assume a semi-operative position as heretofore described so as to move inwardly between the top and bottom rolls upon the strand being parted.

Upon movement of th shaft in the opposite direction, to move the detent into engagement with the other of the cavities in the collar heretofore described, the traverse limiting means will cause the roll lifter support to move outwardly to prevent the free end of the top roll lifting or separatin member from engaging either of the rolls although the strand of yarn may be unduly slack, or broken. This latter feature is particularly provided to facilitate the tying of the ends together or starting up after dofiing and taking up the slack therein manually although the slack in the yarn may be such as to normally permit the roll separating member to engage the rolls and to thus be pulled inwardly to separate the top and bottom rolls.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which- Figure 1 is an enlarged fragmentary elevation with parts broken away and other parts being omitted and showing a portion of the creel, the top and bottom rolls, the yarn guide and the upper ends of bobbins in a portion of a ring rail and also showing the improved stop motion mounted on the rolls stands which support the top and bottom rolls;

Figure 2 is a schematic view, with parts in section, taken substantially along line 22 in Figure 1 and showing the first or original form of the invention in association therewith;

Figure 3 is a partially exploded isometric view showing how the shaft which supports the improved stop motion is mounted and showing the clutch or locking means thereforj Figure 4 is an enlarged fragmentary elevation of the improved stop motion associated with the top and bottom rolls and the roll stands and being an enlarged elevation of the central left-hand portion. of Figure 1,;

Figure 5 is a fragmentary elevation, with parts in section, looking substantially at the right-hand side of Figure 4 and showing the improved stop motion in a partially or semi-operative position, such position being maintained during normal operation of the twister machine;

Figure 6 is a fragmentary vertical sectional view taken substantially along the line 66 in Figure 4 but showing the improved stop motion in a fully operative position as result of the strand of yarn being separated and, in which instance, the roll separating or lifting member is holding the top roll out of engagement with the bottom roll;

Figure '7 is an enlarged vertical sectional. view taken substantially along line l'! in Figure 4 and showing a part of the shaft locldng means or clutch;

Figure 8 is a fragmentary elevation similar to Figure 4 but showing a slightly modified second form of stop motion which is particularly adapted for use when the yarn passes beneath and half around the bottom roll, then passes around the top roll and extends downwardly from the top roll to the usual traveler;

Figure 9 is an elevation looking substantially at the right-hand side of Figure 8 and showin the roll separating member or lifter in a partially or semi-operative position;

Figure 10 is a vertical sectional View taken substantially along the line Ill-i3 in Figure 8 but showing the roll separating or lifting member in a fully operative position, which occurs upon the yarn being broken or unduly slack;

Figure 11 is a third form of the invention which is quite similar to the original form of the in vention, the top roll lifting member merely bein shaped differently to accommodate a top roll of substantially smaller diameter than the bottom roll.

Referring more specifically to the drawings, the numeral IQ broadly designates the frame of a twisting machine comprising a roll stand support or girt H, a creel i2 and an upper yarn guide support l3 which extend substantially the entire length of th machine. The machine also has a bolster rail, not shown, on which suitable spindles, not shown, are mounted for supporting bobbins or spools S or other suitable yarn takeup means. These spools or bobbins .S extend through a ring rail IE, only a portion of which is shown in Figure 1, and which has suitable twister rings (6 fixed thereon through which the bobbins or spools S also extend.

The twister ring 5 may be of any desired construction and is shown in Figure 1 as having a conventional traveler I! mounted for rotation thereon for directing yarn Y to the bobbin or spool S and for effecting twist in the yarn Y while maintaining tension in the yarn. As is well known to those familiar with the art, the ring rail 5'5 reciprocates in a vertical manner in the course of directing the yarn to the bobbin or spool S.

The creel 12 has a plurality of spindles 20 thereon on each of which a yarn package 2| is rotatably mounted and from which a strand of yarn Y-l extends downwardly. It is evident that there may be other packages of yarn disposed in a higher plane than those shown in Figures 1 and 2 for directin one or more strands of yarn Y-2 downwardly to join the strand of yarn Y-l to form the multi-ply strand Y which is subsequently twisted.

The yarn Y extends past and in engagement with a lease bar or rod 23 and then through a yarn guide 24 projecting from the upper yarn guide support H3. The yarn then passes beneath a shaft 25 and then upwardly over a rod 26 from whence the yarn extends forwardly, in one in stance, and over the top surface of a top roll 21, which is of usual construction and which normally rests in engagement with a bottom roll 30 usually of lesser diameter than the top roll 21. The bottom roll 30 usually has a plurality of top rolls 2'! resting thereon in end-to-end relation to each other as shown in Figure 1.

The bottom roll has reduced portions or may be fixed on a shaft 3| which is mounted for rotation in spaced roll stands 32 suitably secured to the upper surface of the roll stand support or girt ll. Each of the roll stands 32 is usually provided with a U-shaped notch or cavity 33 in which the shaft 3! of the bottom roll 30 is rotatably mounted, and which cavity 33 defines a front portion 34 which is utilized in supporting the bearing blocks of the improved stop motion to be later described.

The top rolls 2'! are usually of a type having reduced end portions 35 integral therewith. There is disposed rearwardly of the top rolls 2! a horizontally disposed bar 35 having a plurality a'e a'rso of forwardly extending arms 31 thereon, there being one of these arms 31 disposed'between the proximate ends of adjacent top rolls 21.. The opposed sides of each of the forwardly projectingarms 31' are provided with vertically extending'grooves 40 in which the reduced end portions 350i the top rolls: 21 are loosely mounted for rotational and vertical sliding movement therein. Each of the roll stands 32 is provided with a bifurcated upwardly projecting portion 4| for supporting the horizontally disposed bar 36.

Now, the yarn Y' extends over the upper surface of each of the top rolls 21 and, in'this instance, the yarn extends half way-around the top roll 21, or may circumscribe the roll one or more times, and then passes between the top and bottom rolls 21 and 30 and substantially half way around the bottom roll 3!]. The yarn Y then extends forwardly through a yarn guide, to be presently described, and then downwardly through a lower yarn guide 43 whichis pivoted, as at, on a bar 45. The bar 45 is suitably secured to brackets 46 which are, in turn, suitably secured to a common horizontally disposed bar 41 which is usually mounted for vertical movement on the horizontally disposed girt ll of the frame In. The yarn then extends downwardly through the traveler I1 as heretofore described. The bottom roll 30 is driven by conventional means, not shown, to rotate in a counter-clockwise direction in Figure 2 or in a clockwise direction in Figures and 6. Since the means for I driving the bottom roll 30 is well known to those familiar with the art, an illustration and descrip tion thereof is deemed unnecessary. The bottom scribed may vary from that shown in the drawings and the present invention may be used in association with any type of yarn processing machine wherein the top roll rest upon the bottom rolls and rotate through contact therewith.

. Now, as heretofore stated, the objectof the invention is to provide an improved stop motion which will operate automatically upon the yarn Y being parted between the bite of the top and bottom rolls 21 and 30 and the corresponding spool or bobbin S to cause cessation of rotation of the top roll 21 and to thereby prevent the yarn from being wound several times about the top roll 21 before the parted yarn is" discovered by an operator.

To this end, the improved stop motion comprises a wedge-shaped, beak-shaped or triangularly-shaped roll separator member or top roll lifting member broadly designated at 50; disposed adjacent each of the top rolls 21, and which is provided with forwardly or outwardly diverging upper and lower arcuate surfaces 5| and 52 which may conformsubstantially to the configuration of the peripheries of the rolls 21 and 30 at the bite thereof. This top roll lifting member 50 is preferably made from a friction material, such as leather and the like, to thereby insure that the bottom roll 30 will pull the top roll lifting member rearwardly or inwardly upon the rear or sharp end of the top roll lifting member 50 being moved into engagement with the top and bottom 6". rolls '21 and at the juncture thereof in a manner to be later described.

The roll separating member or top roll lifting member is provided with a'front abutting surface 53 and has a forwardly projecting portion 54 at the upper edge thereof which is provided for pivotally supporting the top rolllifting member 50, as at 55, in the bifurcated upper end of an arm 56 which is an integral part of a roll lifter support or roll separator support broadly designated at 51. The arm 56 extends downwardly and has an enlarged or rearwardly projecting overbalancing portion 60 integral therewith, which is shown as being substantially circular in crosssection in Figure 6. This portion 60 .is pivotally mounted on a shaft 61 which is spaced from the front surface of the bottom roll 38 and is preferably disposed in the same horizontal plane as the axis of the bottom roll 39.

It will be noted that the enlarged portion 69 of the roll lifter support 51 is eccentrically mounted on the shaft 5! with the greater portion of the enlarged portion 60 being disposed rearwardly of the shaft GI or between the shaft 6| and the bottom roll 39. It will also be noted that when the arm of the roll lifter support 51 is in the substantially vertical position shown in Figure 5, the free or rear end of the toproll lifting member 5! is spaced closely adjacent the bite of thetop and bottom rolls 21 and 3B and the abutting surface 53 then engages the rear surface of the arm 56 due to the overbalanced manner in which the top roll lifting member 5!) is mounted. This insures that the free or rear end of the top roll lifting member 50 is spaced from both the top and the bottom rolls while being disposed closely adjacent the juncture or bite of the rolls 21 and 3!].

The enlarged portion of the roll lifter support 51 has the shank 62 of a suitable yarn guidebroadly designated at 63 adjustably secured therein as by a set screw 64. The shank 62 of the yarn guide extends downwardly and outwardly at an angle relative to the bottom roll 30v and is preferably provided with an elongated transverse lyextending loop portion 55. In this instance, the yarn passes half around the bottom roll 39 and then extends forwardly through the loop 65 of the yarn guide 63 from whence the yarn Y extends downwardly throughthe yarn guide 43 and the traveler l1, successively, to be wound about the spool S. Thus, when there is suflicient tension in the yarn Y, the yarn tends to urge the roll lifter support 51 in a counter-clockwise direction in Figures 5 and 6 thus holding the free end of the top roll lifting member 50 in spaced relation to the bite of the top and bottom rolls 21 and 39. Conventional means, not shown, are usually provided on twisters and the like .to cause the yarn to traverse each of the top rolls 21 longitudinally thereof to prevent the yarn from wearing grooves in the peripheries of the top and bottom rolls. Therefore, the inner or rear edge of the top roll lifting member 55 is normally spaced from the bite of the top and bottom rolls 21 and 3B sufficiently to permit the yarn to pass about the rolls Z1 39 without engaging the top roll lifting member during the traversing of the yarn. This is also the reason for providing the transverse elongation of the loop portion 65 on the yarn guide 53. The yarn Y usually passes around the top rolls 21 a number of times before it passes half around the bottom roll 33. However, the yarn is shown as passing only half around the top rolls 21 for purposes of clarity. In order to limit movement of the roll lifter support 51 in opposite directions about the shaft 6|, the roll lifter support 51 has a cavity 56 in the front surface thereof which is loosely penetrated by the shaft 6|. The shaft 6! has a traverse limiting member or cam 6'! adjustably secured thereon as by a set screw 10. This traverse limiting member 6! is disposed within the cavity 66 in th enlarged portion 60 of the roll lifter support 51 and is slightly smaller than the cavity 86 so as to permit oscillation of the roll lifter sup-port 51 about the shaft 6|.

However, the upper and lower surfaces of the traverse limiting member 61 are disposed relative to the upper and lower walls of the cavity 66 so that the upper wall of the cavity 55 engages th upper surface of the traverse limiting member 61 upon normal tension in the yarn Y causing the roll lifter support 57 to be urged in a counter-clockwise direction in Figure 5. Now, upon the yarn Y being parted at a point anywhere along the portion of its length extending between the bite of the top and bottom rolls 2? and 30, respectively, and the traveler [7, the weight of the nlarged portion of! of the roll lifter support 5i combined with the weight of the top roll lifting member 56 urges the top roll lifting member 50 rearwardly or in a clockwise direction from the position shown in Figure 5 to substantially the position shown in Figure (5, or until the free end of the top roll lifting member 50 is in tight enough ngagement with the bottom roll 39 to cause the bottom roll 30 to pull the top roll lifting member 50 rearwardly and to lift the top roll out of engagement with the bottom roll 30. It is evident that the top roll lifting member 50 is pivoted at 55 so the sharp or rear edge of the same may move rearwardly in a substantially straight line, although the pivot point 55 moves downwardly in an arcuate path as it moves rearwardly. The inward or rearward movement of the top roll lifting member 5B is limited by the bottom wall of the cavity 66 engaging the lower surface of the traverse limiting member 61. Although the stop motion devices, comprising the top roll lifting members 58 and the supports 51, are shown to one side of the centers of the top rolls 2'! in Figure 1, the position of each device is determined by the center of gravity of the corresponding top roll sinc it is evident that the top roll must be balanced on the top roll lifting member 50 in order to prevent one of the ends of the top roll from engaging the bottom roll after the yarn in parted. Otherwise, the top roll would continue t rotate and would defeat the purpose of the stop motion devices.

The shaft 6| is oscillatably mounted in bearing blocks 12 and 13 suitably secured adjacent the outer or front surfaces of the portions 34 of the spaced roll stands 32. In this instance, each of the bearing blocks 12 and 13 has a slotted rearwardly extending projection H3 at the upper end thereof which is suitably secured, as by a screw 15, to the upper surface of the portion 34 of the correspondin roll stand 32. The bearing block 12 differs from the bearin block 73, since this bearing block 12 serves as a primary element of a clutch or shaft locking means which will now be described. The shaft 6! is prevented from moving from left to right in Figures 1 and 4 by a suitable collar 16 which is adjustably secured as the shaft 5! by a set screw T! and which slidably and rotatably engages the left-hand surface of the bearing block 12 in Figures 1 and 4. This collar I6 is shown in exploded relation to the bearing block 12 in Figure 3 for purposes of clarity.

The collar 16 also serves to hold a clutch member or collar in sliding rotational engagement with the opposite surface of the bearing block 12 from that which is engaged by the collar it. The clutch member 80 has a recess Bl cut in its periphery and into which a traverse limiting pin 82 projects from the proximate surface of the bearing block 12. The purpose of this traverse limiting pin 82 is to limit cillatory movement of the shaft 6|, on which the collar or clutch member 80 is adiustably secured, as by a set screw 83. The pin 82 is suitably secured in the bearing block 12 as by a pressed fit.

In order to lock the shaft 6| in the desired position, for purposes to be presently described, the bearing block 12 has a cavity or bore 84 in its right-hand surface in Figures 1 and 4, in which a spring loaded detent 85 is slidably mounted. This spring loaded detent 85 is normally urged outwardly with respect to the bearing block 12 by a compression spring 86 disposed within the bore or cavity 8:1. The spring loaded detent B5 is preferably disposed in diametrically opposed relation to the pin 82 relative to the shaft 6|.

The collar or clutch member 80 is provided with a pair of indentations or cavities 9B and 91 which are preferably bridged by a shallow passageway or cavity 92 of less depth than the cavities 9i] and 9!. This recess 92 is provided because of the outer end of the detent 85 being rounded and to assist in leading the detent 85 out of the cavities and 9|, the detent 85 being urged into the corresponding cavity 90 or 9| depending upon the position of the shaft 6|. The outer or left-hand end of the shaft BI is provided with a handle portion 93 which may be manipulated by an operator for shifting the position of the shaft SI for aligning the desired cavity 90 or 9| with the detent 85.

Now, the purpose of the clutch or locking mechanism heretofore described is to provide means for holding the rear ends of the top roll lifting members 50 out of engagement with corresponding top rolls 2! and bottom rolls 30 althrough the yarn Y may be parted. This may be required in tying several ends of yarn in rapid succession, such as in setting up the machine, or it may happen that considerable slack is effected in the portion of yarn extending between the bite of the top and bottom rolls 3'! and 30 and the traveler I! after the ends of the yarn have been tied together. This would require that the yarn be pulled in a reverse direction or upwardly between the rolls 21 and 36 by an operator to take up the slack in the yarn and during which it may may be desirable that the top roll 21 rests in engagement with the bottom roll 30.

Therefore, when an operator desires to move all of the stop motion units, comprising the top roll lifter support 51 and the top roll lifting member 50, to a fully inoperative position, the operator merely moves the handle 93 downwardly in order to move the shaft Bl in a counter-clockwise direction beyond the position shown in Figure 5. The cavity 9| will then register with the detent 85 and the spring 86 will cause the detent 85 to enter the cavity 9! thus holding the shaft 6! in the desired position so the lower surface of the traverse limiting member 51 engages the bottom wall of the cavity 66 to thus prevent rearward movement of the top roll lifting member 30, although the yarn Y may be unduly slack or parted. The pin .82 engages the correspondin wall of the cavity or recess 8| in the collar .80 to insure that the shaft BI is not rotating to where the detent 85 would be disposed beyond the edge of the cavity9l relative to the cavity 90.

, It is evident that, upon the operator subse* quently rotatin the shaft 6| in a clockwise di- 'rection. in Figure 6, the detent 85 then registers with the cavity .90 to lock the shaft 6| so the roll lifter support 51. and the top rolllifting member :50 assume a semi-operative position as the yarn Y passes through the yarnguide 63 under proper tension.

Secondform of stop motion device The second form of stop motion device is shown in Figures 8, 9 and 10. This form of stop motion device difiers only silghtly from the original form of stop motion device and, therefore,

the parts of the second form of stop motion device will bear thesame reference characters as corresponding parts of the original form of stop motion device with the letter a affixed thereto in order to avoid repetitive description.

The form ofstop motion device shown in Figloop portion 65a ofthe yarn guide 63a and thus to the spool S in the manner heretofore described for the original form of the invention.

Thus, the second form of stop motion device differs from the original form in that the shank 62a of the yarn guide 63a is bent forwardly, as at 95, to thus cause the loop portion65a of the yarn'guide 63a to extend in a substantially horizontal plane outwardly of the bottom-roll 30a and to thus position this-loop portion 65aa substantial distance outwardly of =theuvertic-al plane of the front surface of the roll lifter support 51a.

, The yarn, inits course from the top roll 21a. to the spool, then extends over the outer surface of the 'loopportion 65a ofthe yarnguide 63a and thereby urges the roll liftersupport 51a in a counter-clockwise direction in'Figure S provided that there is sufficient tension in theyarn Y-a. The form of the invention shownin Figures 8, 9 and 10 operates in the identical-manner which the original form of the invention operates and, therefore, a description thereof is deemecl'unnecessary. In this form of the invention, the yarn Yfl cannot pass between the top roll lifting member 50a and the rollsz'la and 30a as it traverses the rolls lengthwise thereof.- Therefore,-

theloop portion 65a extends outwardly to one sideonlyof the shank62a. The yarnguide63a also differs fromthe yarn guide 63 in that opposed endsof the elongated loopportion 65a-are curved outwardlyatQB to thereby preventthe yarn Y .a from sliding off the-ends of the-loop portiontiabf'theyarn guide 63a.

It is evident. that the loop :portion 65a-maybe omittedfrcm the yarn guide63a and inwhich in-s stance, the yarn guide 63a would merely, be L-shaped to provide a transverse portion, inlieu oflthe portion 65a, over and in engagementwith which the yarn Y+a passes. Since the yarn can: not pass-betweenthetop roll lifting member 0q, and therolls Zlaandifla, it may bedesirable to provide a pair .of the stop motion devices for each top roll, the devices then being spaced from each other and having a common yarn guide extending .therebetween to thereby insure that the top roll will be properly balanced. This being an obvious expedient, a detailed description and illustration thereof is deemed unnecessary.

Third form of twister stop motion device In Figure 11, there is shown a third form of stop motion device which is substantially the same as the original form of the invention. However, the stop motion devices heretofore described have been described in association with a top roll of larger diameter than the bottom roll. The form of the invention shown in Figure 11 is particularly adapted to be used with a top roll of smaller diameter than the bottom roll. Since the parts and manner of operation thereof associated with the form of the invention shown in Figure 11 are substantially the same as those shown in the original form of the invention, a detailed description thereof is deemed unnecessary and the parts shown in Figure 11 shall bear the same reference characters as those applied to like parts associated with the original form of the invention with the letter b affixed thereto.

The only difference between the form of the invention shown in Figure 11 and the original form shown in Figures 1 to 7, inclusive, is the shape of the top roll lifting member or roll separating member 56b. In the original form of the invention, the length and degree of arc of each of the surfaces 5| and 52 is substantially the same.

It will be observed in Figure 11 that the upper arcuate surface 5lb| is of substantially less radius than the lower arcuate surface 521;, the radii of the surfaces 5| b and 52b conforming substantially to the-radii of the top and bottom rolls 21b and'3llb so the surfaces 5!!) and 52b are engaged for substantially their full lengths by the top and bottom rolls 21b and 30?) respectively, when the top roll lifting member 5% is in the fully operas tive position shown in dotted lines in Figure 11.

When the top roll lifting member b is in the dotted line position, it is evident that the'top roll 21b is elevated to the dotted line position shown. It is evident that, since the upper arcuate surface 5 l b is of a substantially less radius than the lower arcuate surface 521), this surface 5Ib terminates a substantial distance short of the'rear or outer end of the top roll lifting member50b while, in the original form of the invention, the arcuate surface 5| extends from the rear end of the top roll lifting member 50 to a point immediately adjae cent the front end thereof.

In order to accommodate the increased diameter of the bottom roll 30b a1s shown'in Fi ure 11, it is evident that the shankv 62b of the yarn guide 631) is substantially longer than the shank 62 of the yarn guide 63 shown'in Figure '5 so the yarn Y need not necessarily extend upwardly as it leaves the bottom surface of the bottomroll 39b. The shank 62b may be of the same length as the shank 62 if so desired.

It is thusseen that we have providedan proved stop motion for twisters which maybe moved manually into a fully inoperative position when so desired even though the yarn maybecome parted .andwhich may also be moved into a semi operative position, in, which instance-the free or rear end of. the wedge=shaped1top roll li tin memberisfdisposed closely adjacent :the bite of the t p. andbottom-rolls 21 and 139 with means responsive to the yarn being parted or becoming unduly slack between the bite of the rolls and the spool on which the yarn is being wound for moving the top roll lifting member inwardly to be engaged by the rolls and thus pulled further inwardly to elevate the top roll out of engagement with the bottom roll and to thereby cause cessation of rotation of the top roll although the bottom roll may continue to rotate.

In the drawings and specification, there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

We claim:

1. An improved stop motion for a twisting machine or the like for processing yarn, said twisting machine having at least one driven bottom roll and at least one top roll resting upon the bottom roll and being driven through contact with the bottom roll, said machine also having means onto which the yarn is directed from the rolls and being disposed below the rolls and said machine also having means for maintaining tension in the yarn, said stop motion comprising a horizontally disposed shaft disposed forwardly of the bottom roll and in substantially parallel relation to the axis of said bottom roll and also being disposed in substantially the same horizontal plane as the axis of said bottom roll, a roll lifter support oscillatably mounted on said shaft and having an upwardly extending arm thereon, means normally urging said upwardly extending arm towards the bite of the top and bottom rolls, a top roll lifting member pivotally mounted on said arm and extending towards and normally terminating closely adjacent the bite of the top and bottom rolls, said top roll lifting member having a relatively sharp edge remote from said arm and being provided with upper and lower outwardly diverging arcuate surfaces thereon, a yarn guide extending from the roll lifter support and being disposed beneath said shaft and through which the yarn extends in its course from the rolls to the means onto which the yarn is directed, the tension in the yarn normally holding the top roll lifting member out of engagement with the rolls, and the proximate surfaces of said top and bottom rolls rotating in a direction away from the top roll lifting member whereby, upon said yarn being parted at a point between the rolls and the means onto which the yarn is directed, the relatively sharp edge of the top roll lifting member will move towards and into engagement with the proximate surfaces of the top and bottom rolls thereby being pulled further into position between the top and bottom rolls to lift the top roll out of engagement with the bottom roll to thereby prevent further rotation of the top roll.

2. An improved stop motion for a twisting machine or the like for processing yarn, said twisting machine having at least one driven bottom roll and at least one top roll resting upon the bottom roll and being driven through contact with the bottom roll, said machine also having means onto which the yarn is directed from the rolls and being disposed below the rolls, and said machine also having means for maintaining tensionin the yarn, said stop motion comprising a horizontally disposed shaft disposed forwardly of the bottom roll and in substantially parallel relation to the axis of said bottom roll and also being disposed in a lower horizontal plane than the bite of said top and bottom rolls, a roll lifter support pivotally mounted on said shaft and having an upwardly extending arm thereon, means normally urging said upwardly extending arm towards the bite of the top and bottom rolls, a top roll lifting member pivotally mounted on said arm and extending towards and normally terminating closely adjacent the bite of the top and bottom rolls, said top roll lifting member having a relatively sharp edge remote from said arm, a yarn guide extending from the roll lifter support and disposed beneath said shaft and through which the yarn extends in its course from the rolls to the means onto which the yarn is directed, the tension in the yarn normally holding the top roll lifting member out of engagement with the rolls, the proximate surf-aces of said top and bottom rolls rotating in a direction away from the top roll lifting member whereby, uponsaid yarn being parted at a point between the rolls and the means onto which the yarn is directed, the relatively sharp edge of the top roll lifting member will move towards and into engagement with the proximate surfaces of the top and bottom rolls thereby being pulled further into position between the top and bottom rolls to lift the top roll out of engagement with the bottom roll to thereby prevent further rotation of the top roll.

3. In a structure according to claim 2, means for limiting movement of the arm of the roll lifter support toward the bite of said top and bottom rolls to normally cause the top roll lifting member to assume a semi-operative position closely adjacent the bite of the top and bottom rolls, means operable manually for rotating the roll lifter support so the arm thereof is moved away from the bite of the top and bottom rolls, and means for locking said roll lifter support in the latter position whereby, although the yarn may be parted, the top roll lifting member will not move inwardly towards the bite of the rolls sufiiciently to engage said rolls.

4. An improved stop motion for a twisting machine or the like for processing yarn, said twisting machine having at least one driven bottom roll and at. least one top roll resting upon the bottom roll and being driven through contact with the bottom roll, said machine also having means onto which the yarn is directed from the rolls and being disposed below the rolls, and said machine also having means for maintaining tension in the yarn, said stop motion comprising a horizontally disposed shaft disposed forwardly of the bottom roll and in substantially parallel relation to the axis of said bottom roll and also being disposed in a lower horizontal plane than the bite of said top and bottom rolls, a roll lifter support pivotally mounted on said shaft and having an upwardly extending arm thereon, means normally urging said upwardly extending arm towards the bite of the top and bottom rolls, a top roll lifting member pivotally mounted on said arm and extending towards and normally terminating closely adjacent the bite of the top and bottom rolls, said top roll lifting member hav-- ing a relatively sharp edge remote from said arm, a yarn guide extending from the roll lifter support and disposed beneath said shaft and through which the yarn extends in its course from the rolls to the means onto which the yarn is directed, the tension in the yarn normally holding the top roll lifting member out of engagement with the rolls, the proximate surfaces of said top and bottom rolls rotating in a direction away from the top roll lifting member whereby, upon said yarn being parted at a point between the rolls and the means onto which the yarn is directed, the relatively sharp edge of the top roll lifting member will move towards and into engagement with the proximate surfaces of the top and bottom rolls thereby being pulled further into position between the top and bottom rolls to lift the top roll out of engagement with the bottom roll to thereby prevent further rotation of the top roll, traverse limiting means on said shaft for limiting the arc of movement of the top roll lifter support to thereby cause the relatively sharp edge of the top roll lifting member to remain closely adjacent the bite of the top and bottom rolls while the yarn is passing through the yarn guide under tension and to also limit movement of the top roll lifting member upon said top roll lifting member being pulled between the top and bottom rolls through engagement therewith upon the yarn being parted.

5. In a yarn processing machine, such as twisters and the like, having at least one driven bottom roll and at least one top roll resting upon the bottom roll and being rotated through contact with the bottom roll and take-up means for the yarn disposed beneath said rolls and wherein the yarn passes between the rolls and thence to the take-up means under tension, an improved stop motion for the top roll comprising a substantially triangularly-shaped top roll lifting member disposed adjacent the bite of said rolls, the proximate surfaces of said rolls rotating in a direction away from said lifting member, a support disposed in a lower horizontal plane than said lifting member and having an upwardly extending arm thereon to which the lifting member is pivotally connected, means pivotally supporting the support in said lower horizontal plane, means engageable by the yarn under tension in its course from the rolls to the take-up means for normally holding the support and the top roll lifting memtween the rolls and the take-up means for moving the corresponding edge of the top roll lifting member into engagement with the rolls at the bite thereof, whereupon the rolls will pull the top roll lifting member inwardly between the bite of said rolls to thereby lift the toproll out of engagement with the bottom roll to cause cessation of rotation thereof, means operable manually for rotating the support so the arm thereof is moved away from the bite of the top and bottom rolls, means for locking said support in the latter position whereby, although the yarn may be parted, the top roll lifting member will not move inwardly toward the bite of the rolls sufficiently to engage said rolls, means for locking said support in said semi-operative position and means on said support for permitting pivotal movement thereof while in a semi-operative position to permit the same to pivot towards said rolls upon the yarn being parted.

THOMAS M. RIPLEY.

CARSON P. ELLIS.

FRANK G. POWERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,047,124 Boyd Dec. 10, 1912 1,861,103 Wild May 31, 1932 1,885,423 Fenton Nov. 1, 1932 2,034,483 Olson Mar. 17, 1936 FOREIGN PATENTS Number Country Date 344,849 Italy Nov. 27, 1936 

